Correlation between Heart Rate Variability and Bladder Sensations During Filling and Voiding Phase of Urodynamic Study in Patients with Myelopathy

Objective: The objective of this study was to correlation between heart rate variability (HRV) and bladder sensations during filling and voiding phase of urodynamic study (UDS) in patients with myelopathy. Materials and Methods: Myelopathy patients (traumatic and nontraumatic) within 6 months of illness were included in the study. Demographic data, etiopathological diagnosis, and urinary complaints were noted. UDS was performed and simultaneous HRV calculated at each event of filling and voiding phase by recording and calculating standard deviation of normal-to-normal (NN) interval (SDNN), root mean square of successive differences, total power (TP), average heart rate, high frequency (HF), low-frequency (LF) ratio, and data analyzed. Results: The study included 30 patients (23 males) with a mean age of 31.2 years (range 18-60 years, standard deviation 11.6). The mean of LF in normalized units showed an increase from 43.6 +/- 14.1 at baseline to 48.9 +/- 17.4 at strong desire to void (SDV) and at urgency to 44.1 +/- 14.5. HF at baseline 40.4 +/- 14.1 reduced to 36.4 +/- 12.8 at SDV and rose at urgency to 41.2 +/- 13.2. LF/HF at baseline was 1.3 +/- 0.8, which increased to 1.6 +/- 1.1 at SDV and reduced at urgency to 1.2 +/- 0.6. Significant change in mean value was seen in TP (P = 0.01) and SDNN (P = 0.009) at first desire to void. Significant positive trend was seen in TP (P = 0.048) and SDNN (P = 0.042) during filling. Conclusion: Comparison of HRV measures failed to show significant rise in sympathetic or parasympathetic component in myelopathy patients during UDS and requires more critical evaluation.